For many hearing loss patients, bone conduction hearing aids offer a better solution than more conventional acoustic/air transmitting hearing aids. Indeed, for some patients bone conduction hearing aids offer the only solution. Bone conduction hearing assistance generally involves vibration of the patient's mastoid bone to improve hearing perception. In a typical bone conduction hearing aid, sound sensed by a microphone is converted to an electrical signal and amplified. The amplified signal is then received by a small transducer which vibrates the mastoid bone. Strategic placement of the transducer on the user is essential in order to achieve optimal results. For example, with some bone conduction hearing aids the transducer is placed against the skin behind the ear, while with others the transducer is placed on the forehead. Still others require surgical implantation of the transducer directly into the mastoid bone for better transmission of vibration. However, all of these approaches have significant disadvantages.
One particularly effective approach has been to mount the transducer on an in-the-ear (“ITE”) structural member. The structural member is inserted in the patient's ear canal so that the transducer is positioned adjacent the mastoid bone. While this approach has been shown to provide excellent vibration transfer characteristics, it is unavailable for patients with ear canals too small to receive the transducer, such as patients who suffer from congenital atresia—a condition where the ear canal is narrowed or, in some cases, entirely closed off from the ear drum.
In any case, space for accommodating parts within an earpiece shell of a hearing aid is very limited, particularly within ITE hearing aids. Thus, the efficient use of space within a structural member is a highly significant and limiting factor.
What is needed, therefore, is technology to increase the space for working components. What is also needed is technology to allow smaller earpiece shells of ITE hearing aids to be manufactured for persons with smaller ears and associated ear structures.